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Discussion Starter #1
Hello,

My wife was driving her 99 9-3 SE yesterday and had a problem. The car was running great. She went to the mall for about 20 minutes, came out and the car would not start. Turns over fine, just won't start.

I'm wondering where to start. I subscribed to Alldata tonight for this model. I'm thinking maybe the fuel pump, fuel pump relay, or maybe the control module.

Can anyone help me get started in the right direction?

If it makes a difference, it was very hot out. About 105* F.

Thanks for any help you may have. I would love to be able to repair this myself rather then surrender to the mechanic.

Bob
 

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Discussion Starter #3
I did manage to get to the relays under the dash. I swapped out a few with the same type from under the hood. No start as of yet. I seem to be getting a slight smell of fuel, so maybe it's an ignition problem? Any guesses?
 

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bhaubold said:
I did manage to get to the relays under the dash. I swapped out a few with the same type from under the hood. No start as of yet. I seem to be getting a slight smell of fuel, so maybe it's an ignition problem? Any guesses?
With that smell of fuel, the DI rears its costly ($350) head..
But assure that you do have the fearsome four ( timing, spark, compression and fuel).
 

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Discussion Starter #5
The car was running perfectly when parked. Twenty minutes later, no start. How does one test the DI?


Thanks very much for your help. I'm really lost at this point.Is the DI a common part to go out? Does it go just like that?

Bob
 

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I'm wondering. If I turn the DI over, install the plugs and ground them, turn the starter over and look for spark. If I get no spark at all, would this indicate somethin other than the DI? Does the DI completely go out or just start to lose performance over a period of time? Or, both?

I don't mind spending the $$$ on a new DI, just would like to be sure that's the problem.

Thanks,

Bob
 

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bhaubold said:
I'm wondering. If I turn the DI over, install the plugs and ground them, turn the starter over and look for spark. If I get no spark at all, would this indicate somethin other than the DI? Does the DI completely go out or just start to lose performance over a period of time? Or, both?

I don't mind spending the $$$ on a new DI, just would like to be sure that's the problem.

Thanks,

Bob
Wow, your good. That basically is the testing procedure in a nutshell! I was going to suggest this testing procedure. So yes, that is a good way to test the DI. Has the check engine light turned on? From my limited understanding of the Trionic engine management system, often a fault code is associated with a failed DI.

Usually the DI just goes, or a cylinder will misfire, but its not usually associated with a loss of performance over time. If no spark or all spark occurs during the testing then you may want to look at other possibilities.
 

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Discussion Starter #9
The thing that is bothering me is, the car ran fine. Parked it to go shopping for 20 minutes, came out, and no start.

I did find a resistance that the crank position sensor should read. I'll check that first, then see how the DI checks out.

Thanks for your help.
 

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Battery ?

I had a '99 9-3 SE 2.3 and was surprised how the battery can die from one minute to the next. I was driving normally, parked and switched off to answer a phone call. No way it would start up... the battery was DEAD.
 

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By the way bhaubold, how many miles are on the car?
 

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Discussion Starter #12
The battery is very good. The starter cranks without problem. Just doesn't start. Not even a hint of wanting to start. As I said before, after cranking the starter and removing a spark plug, I can smell fuel and the plugs are slightly wet. Which leads me to the ignition.


Since we have another car to drive, and I have been very busy at work, I have not tested anything as of yet. Sunday, I will read the resistance of the crank position sensor, then try to see if any spark is coming from the DI. I don't think I will see any though, as the car doen't even pop like it's going to start. Just cranks away as if you had no ignition at all. I did swap out some of the relays under the dash. Fuel, ignition. I just moved same type to other positions and then back again thinking maybe one was bad. No help.

The car has 88,000 miles at this time. We have had the car the last 20,000 miles. All has been well until now, except for the SID missing pixels.

Thanks for your help.

Bob
 

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As I said before, after cranking the starter and removing a spark plug, I can smell fuel and the plugs are slightly wet. Which leads me to the ignition.
I think you are correct. As far as I know, the ecu does not start the fuel pump until after it detects a signal from the crank sensor. The sequence is something like this:

ignition on
starter on
CPS signal to ecu
ecu turns on fuel pump
spark

You can also listen for the fuel pump to come on if you flip up the rear seat, and put your ear above the inspection cover while someone cranks the engine.
 

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You should also briefly hear the fuel pump bring the pressure in the fuel line up when you have the ignition on (position right before you engage the starter). I hear mine when I do that.
 

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Slaab4life said:
You should also briefly hear the fuel pump bring the pressure in the fuel line up when you have the ignition on (position right before you engage the starter). I hear mine when I do that.
Do you mean the pump kicks on to prime the line? I have seen that posted before, but could never hear it. What does that do?

I thought the fuel circulates continuously through the pump, filter, fuel rail, and FPR, any time the pump is runs, and the fuel not used by the injectors is returned to the tank via the return line (?)
 

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PMI said:
Do you mean the pump kicks on to prime the line? I have seen that posted before, but could never hear it. What does that do?

I thought the fuel circulates continuously through the pump, filter, fuel rail, and FPR, any time the pump is runs, and the fuel not used by the injectors is returned to the tank via the return line (?)
I believe you are correct on the routing of the fuel, but for some reason my pump does briefly whirrr up before startup. I think it is just a pressurizing thing prior to ignition. Taking a fuel filter off just after a drive is probably quite different than doing so the next morning. So after some sit time the pressure in the line is lower, so the pump kicks in for probably a second to get the pressure back up to par. If their is extra pressure I bet the FPR sends the remainder back to the tank.
 

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Slaab4life said:
I believe you are correct on the routing of the fuel, but for some reason my pump does briefly whirrr up before startup.
I unplugged the DIC this evening so I could hear the pump motor more clearly. Someone else cranked the car while I put my ear over the inspection cover. No sound when the ignition came on. Pump motor can be heard when the engine cranks, but not until then. There could be differences between the Motronic system and the T5, which could account for this, not sure.

On the other hand, I think the FPR is the same for the turbo and n/a models. It is a simple device and I would not think it can maintain pressure for more than a second with the pump off. If pressure were to persist for any length of time, the turbo engine would have a problem.

Normally the FPR responds quickly to pressure changes in the intake manifold. If it did not, then the fuel pressure would not go up and down with the boost like it is supposed to. Put another way, the fuel pressure has to be stable relative to the intake air pressure and follow the manifold pressure up and down. That is what the FPR vac line is for, and why I am a bit doubtful that you can actually "prime" the fuel lines in any meaningful way.

The fuel pump kicking over on ignition could be for some other reason though, related to the Motronic ecu... good to know, in any case!
 

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PMI said:
On the other hand, I think the FPR is the same for the turbo and n/a models. It is a simple device and I would not think it can maintain pressure for more than a second with the pump off. If pressure were to persist for any length of time, the turbo engine would have a problem.
Any idea at what point max fuel pressure is achieved (in the vacuum line that is). I had a little problem a month or so back where I found that the vac line to the FPR had bent itself (don't ask how) and was very restricted, if not completely blocked. Car just kept chugging along as if nothing was going on. Though highway fuel mileage may have been effected. I think I dodged a bullet with that one...had I owned an SE model, who knows what I might have done. The fuel pump thing must be a Motronic/Trionic difference. I might explore the reasoning behind this better at a later time.
 

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Any idea at what point max fuel pressure is achieved (in the vacuum line that is).
On your model, no idea.

I had a little problem a month or so back where I found that the vac line to the FPR had bent itself (don't ask how) and was very restricted, if not completely blocked.
As you said, it will not do much harm on your car. If there is even a little air passage, the FPR will work just fine. Even if you bocked it on purpose, most likely only your fuel consumption would increase.
 

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So then, I believe it is the DI. I believe this unit can be greatly improved by a cooling vent sysem...It has been around for 15 or more years now - have there been any real improvements at all ??

Other makes use the DI, I think, and I imagine the components are identical...
As far as the car continuing to run "perfectly" right up to breakdown ; the computer continuously adjusts all systems for ideal operation ( a cover-up of sorts)..

Yet, if it is true that a failing DI always gives some warning before " dieing ", I would continue to check out cheaper/easier solutions.
Ensure that all is "plugged in"...

Another thing, if the DI fails, should not the plugs be soaked with gas rather than just slightly wet ???
 
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